Kidney Disease in Cats

A couple of clients recently requested that I post about kidney disease in cats. It's been a while since I have done so.

I previously wrote THIS about renal disease management but it was really just a few words about somebody else's handout that I linked to.

There were two specific questions I wanted to answer for starters.

#1 - Why are the kidneys so trouble-prone in cats? We don't know. Cats, being desert animals, have a huge reserve of kidney function built in, which is important because, unlike the liver which can regrow functional tissue, when kidney tissue dies it is not replaced. In nature, kidneys only need to last long enough to ensure propagation of the species, which as you know can be accomplished several times by cats before they are two years old. So when we see kidney disease in older cats it may just be that it's a part wearing out, like tires on a car.

But we also know certain things can contribute to premature loss of kidney tissue and a decline in function. Untreated bacterial infections (most commonly dental disease) can cause bacteria to enter the bloodstream where they are filtered out by the kidneys and set up housekeeping. Some cats have a genetic kidney defect known as polycystic kidney disease (PKD) that leads to renal failure in middle age - Persians and Himalayans are especially prone to this. Some cats develop renal lymphoma, a type of cancer formerly associated with feline leukemia virus infection but now most commonly seen in cats whose owners smoke. There is also a theory that certain vaccines which use a cell line derived from feline kidneys might be leading to an immune system attack on kidney tissue (we do not use those particular brands of vaccine).

#2 - How much urine do healthy cats normally produce and how can an owner quantify their own cat's urine output in the real world? Normal urine output in the cat is under 50 ml/kg/day. That's about (ok doing math in my head now) 8 oz for an 11 lb cat, more-or-less. Of course with cat's using a litter box it can be hard to tell how much a cat is urinating (volume) and how often, which is one major reason I strongly suggest using scoopable litter.

Urine balls can be easily quantified, and over time you can get a sense of how many times a day your cat urinates and how big the balls tend to be. What's important is that you make not of changes and bring them to your veterinarian's attention. My own cats normally urinate 2-3 times a day, and the bigger cat has bigger urine balls than the smaller one so I can often tell whose is whose.

If you notice that your cat is producing larger urine balls, and more of them, the two things that come to mind that we have to rule out are kidney disease and diabetes. If the urine balls are smaller and more numerous we need to rule out Feline Lower Urinary Tract Disease, which sometimes means an infection is present (but not always).

Here at Cat's Meow Veterinary Clinic we do not measure urine output directly - cats don't tend to go along with such plans. We measure urine specific gravity (concentration) - cats that produce dilute urine are automatically going to produce a higher volume of urine, but the number we track is USG. The exception is in terminal end-stage renal failure where only scant amounts of very dilute urine are produced, right before none at all is produced - cats are typically euthanized before things reach this point.

I hope this sheds some light on the subject. Kidney disease is one of the most common things I manage in my older patients.

This Hinky Blog Format

Try as I might, I simply CAN NOT get this format to do what I want. So in order to see ALL my lists and gadgets you have to scroll all the way down to the bottom of the page and look on the right side for the Donate to Cat's Meow Charitable Fund button, my Favorite Links list, Recommended Reading list, and the gadget to subscribe to my blog.

I'm sorry. Complain to Blogspot. They are just weird.

Upper Respiratory Infections - Human and Feline

As I sit at home this holiday weekend, trying with marginal success to fight off this nasty cold/bronchitis/laryngitis, I thought I would address some of the issues my clients express concern about with human and feline "colds".

Firstly, I did NOT catch this bug from any of my patients. Humans cannot catch feline upper respiratory viruses - most of those are due to FELINE herpesvirus, and most of the rest are due to FELINE calicivirus. I almost certainly caught my illness from the sick toddler I sat next to on the flight from LAX to Minneapolis, or perhaps in one of the three airports I was in that day, or even at the very busy shopping mall the next day.

Secondly, I am always a little concerned about spreading this sort of thing to my patients or my own cats because it IS possible for a few of the hundreds of human cold viruses to be spread to cats. This is known as a reverse zoonosis or an (and I like this word better, it's so scientific-sounding) anthroponosis. Fortunately, if a cat should be unlucky enough to catch it from me, it would tend to be fairly mild and self-limiting, and would not be able to spread on to other cats or back into humans - it would come to a dead end in that particular cat.

Thirdly, if this had been influenza instead of a cold (it's far too mild to be flu), I would have some serious concerns about spread to cats, but only if I had failed to get immunized against H1N1 influenza. That is the strain that was in the news so much a couple of years ago - I was vaccinated against it then, and I noted that it is also a component of this years routine annual flu shot. H1N1 has in the past spread to an unfortunate few cats and had a mortality rate of about 50%, so I consider it imperative that I protect myself as a way of protecting my patients and my own pets, along with humans.

Lastly, let's go back to that nasty feline herpesvirus. This is the bug that causes the majority of feline upper respiratory disease AND nontraumatic eye disease. It is probably the most common pathogen in cats, and one we have vaccinated cats against for decades. Being a herpesvirus, cats can only catch it once - then they have it, for life. So one would think that vaccinations at that point would have no value. But it turns out that cats with strong immunity to the virus from annual vaccinations do a better job of fighting the darned thing when they have those seemingly inevitable "recrudescences". Back before the recession, when most of my patients were current on their annual FVRCP-C vaccination, I rarely saw cats with upper respiratory or herpes-related eye problems that warranted any treatment whatsoever. But now that so many cats are overdue on vaccinations and their immunity is waning, medical intervention and good home nursing care are much more necessary.

So I guess the gist of this post is (big surprise here): get your annual flu shot, and get your cat vaccinated annually, too. The alternative is much bigger vet bills, and often a much sicker cat.

Here is my current likely nemesis - a picornavirus (actually, a whole cluster of the little devils - if you look close you can even see their horns and cloven feet):

New Year's Holiday Hours

We will be closed all day Saturday Dec 31 through Monday Jan 2. This year the Rose Parade and bowl games are on Monday (I have been told this is due to the NFL Sunday football broadcast rules). So I get a 3-day weekend to try to get my voice back!

Happy New Year, everybody! Have fun and drive safely.

Laryngitis

Well, it's that time of year again. My first day back in the office after Christmas vacation and I suddenly have a whopping case of laryngitis.

This, for those of you who don't know, appears to be my specialty. It's an annual wintertime tradition, and can have effects that linger for many weeks. So I am trying to not talk AT ALL. Of course, it's not actually going according to plan. Writing every thought down is hard, so I am whispering to my assistant. Bad idea. Sigh.

I can't even hum holiday tunes without making things worse. But the cats are happy about that.

Christmas Vacation Hours

I'm headed off on my annual pilgrimage to the frozen wastelands of the Upper Midwest. From tomorrow (Thursday Dec 22) through Tuesday Dec 27 the office will be open limited hours and only for administrative and retail purposes. Hours will be:

Thurs Dec 22 - 9 AM to noon and 5 to 6 PM
Fri Dec 23 - 9 AM to noon and 5 to 6 PM
CLOSED ALL DAY SAT Dec 24, Sun Dec 25, and Mon Dec 26
Tues Dec 27 - 9 AM to noon and 5 to 6 PM

If your cat needs medical attention during this time, please call Veterinary Specialists of the Valley at 818-883-8387.

Have a very Merry Christmas!!

The Cat's Meow Charitable Fund

In these difficult economic times we are encountering more and more hardship cases where long-term clients have encountered unforeseeable economic hardship followed by their beloved cat becoming seriously and unavoidably ill, or someone adopts a stray cat who turns out to be pregnant (and that certainly entails unexpected expenses), and occasionally someone presents us with an injured stray cat or kitten that needs medical or surgical care AND a home (and needs to stay here or in foster care in the meantime).

A charitable fund to help underwrite the often tremendous costs of some of these cases is something I have considered starting for a long time. Dr. Alice Villalobos started her Peter Zippi Fund for helping clients pay for cancer treatments for their pets in this same way, and it has helped hundreds, if not thousands of animals over the years.

For the time being, The Cat’s Meow Charitable Fund will be just an internal funding mechanism for subsidizing care for certain of our cases which we have determined would most benefit from it. We are accepting donations in any amount to the fund. They are not tax-deductible at this time, but we will be looking into the feasibility of taking that step. You can mail us a check – make payable to: Cat’s Meow Veterinary Clinic but please put “Cat’s Meow Charitable Fund donation” on the memo line. You can also ask to have your donation added to your bill when you are paying at the front desk.

I look forward to telling our clients about the kitties we (and YOU) have helped through this fund!

ETA on 12-17-11: A very kind person dropped by yesterday to make a very generous donation to the CMCF. S/he has been a FB fan for a while and saw the post about the fund. Huge thanks to ______ for your kindness!